Typically, in a chair used in a room or a seat in a vehicle, a cushion material or a soft pad whose surface is covered with a cover material is frequently used in a portion to be touched by a human body (e.g., a seat surface and a back rest). Various arrangements are employed for fixing such a cover material.
Among the arrangements, as an arrangement to fix a middle of the cover material and concealable from the outside, there has been known an arrangement where a wire is provided in a groove of the cushion material, clips are arranged on a back of the cover material, and the clips are engaged with the wire to fix the cover material from the back thereof.
In this arrangement, a reverse claw-shaped hook to be engaged with the wire and a guide lever along the hook are formed on a bottom of a portion that locks a locking hem. For introducing the wire into the hook, the guide lever is elastically deformed to be apart from the hook to allow the wire to pass through a gap between the guide lever and the hook.
As such a locking arrangement, there has been known an arrangement in which, after a locking hem extending along the wire and having a bulging tip end is formed on a back of the cover material, and a chuck having a pair of locking claws is formed in the clip, the chuck pinches the tip end of the locking hem. In this arrangement, an interval between the clips to be set on the locking hem is freely determinable or adjustable. The hook and the guide lever project straight from the bottom of the chuck, i.e., a surface opposite to the pair of locking claws (see Patent Literature 2).
In the above arrangement, there has been proposed an arrangement in which an elongated hole formed on the locking hem and a stopper piece formed in the clip are engaged with each other. In this arrangement, the engagement of the stopper piece with the elongated hole prevents the clip from unnecessarily moving along the hem. The chuck, hook and guide lever to be used here have the same shape as those in the above arrangement (see Patent Literature 3).